(This page uses style sheets.)
The wide range of OSS available means that for many functions there are a number of different applications available. The choice of which application to use is not always clear cut and sometimes the final choice will be determined by the preferences of the person making the decision.
The reference model used in these guidelines must therefore be treated as an example of a system which is known to work, rather than a recommendation of a system which should be used in all circumstances.
The guidelines discuss the matters which decision makers should take into account and it may well be that they will come to different, but equally valid, conclusions. In any case, local constraints on the Administrator may require a different model to be chosen.
The possible choices for each group is discussed in detail in Chapter 11 for the Principal groups and Chapter 12 for the Subsidiary groups.
There are some useful reference web sites which contain lists of OSS applications, showing what is available and which of them are candidates for replacement of which proprietary applications. http://linuxshop.ru/linuxbegin/win-lin-soft-en/ is an example.
http://www.osafoundation.org/desktop-linux-overview.pdf contains details of many of the applications discussed below and is therefore another place where Administrators can obtain further information.
One of the strengths of OSS is that it is modular and can be put together in many different ways, allowing systems to be tailored to meet specific needs. This modularity is possible because OSS conforms to open and publicly available interfaces. Unfortunately this flexibility can sometimes be its failing, as Administrators can be daunted by the choice available. There are many organisations that can provide help and support, just as there are in the proprietary market.
Note that not all functional groups have reference choices, either because of the lack of relevant case studies or because netproject were unable to assess properly the relevant products within the scope of this study.
The detailed Reference Choices for the desktop are listed in Appendix D and for the server in Appendix E. In addition netproject have demonstrated a way of installing desktops which makes the installation very simple. The relevant code is set out in Appendix F.
The operating system is GNU/Linux from the Red Hat 8.0 distribution. The user interface is based on Gnome which is part of the Red Hat distribution, but the Gnome-based Ximian XD2 desktop is well worth considering. Red Hat, in this distribution, have tried to merge the KDE and Gnome user interfaces.
The filesystems containing binaries (such as /usr) are mounted “read-only” to stop users altering their contents and the remaining ones are mounted “noexec” to stop code being run from them. To enforce this, the user interface should not allow users to run programs other than through predefined interfaces. This means that command line access or the ability to create or change menu items or icons has to be removed. The machines should have no floppy or CD/DVD drives thereby restricting (but not stopping) other filesystems being attached locally.
The filesystems containing volatile user-based data are mounted from a central NFS server. User authentication is done against a central LDAP database.
Central DNS servers do IP address and name resolution and a DHCP server provides the desktop's network configuration details at boot time.
The major desktop functions are delivered as follows:
OpenOffice.org is chosen because:
If the Administration is migrating from a Windows environment, OpenOffice.org can be run on Windows, giving users initial contact with the new software in a familiar environment.
It has some of the best Microsoft file format integration.
It is becoming the de facto alternative to Office.
Evolution is chosen because it has a very similar user interface to Outlook and so will be easy to learn for many people. It also has some very useful features such as Virtual Folders. However Evolution does not connect to Exchange version 5.5 (although apparently one is planned) and, so if the Administration is using this version, a web based OSS groupware solution will be necessary at the moment (unless a proprietary solution is chosen). Kmail on the other hand supports S/MIME whereas Evolution does not (although there are plans to do so) and Kmail has recently been developed to run as a client against the Kroupware groupware server. The choice is finely balanced therefore and depends upon the immediate needs and the current setup.
Evolution is chosen for personal calendaring and contact management. Groupware is difficult with OSS at the moment, only web based solutions are really available although recently the Kroupware project has produced a solution using Kmail as the client. Hence for an truly OSS solution then a browser would be used for groupware access.
Galeon is chosen because it is a fast, single-function browser that has a nice user interface. Mozilla is an alternative if a full product including mail reader and address book facility is required. Mozilla would also be the choice if the Administration is currently using Windows desktops, and the new browser is required to run in the existing environment to allow users initial contact with the new software in a familiar environment.
A web based content management system such as Aswad would be the choice. However, the Aswad project seems to have stopped and so another choice is now needed.
Personal databases are either based on MySQL or a web-based groupware product such as phpGroupWare.
The operating system is GNU/Linux from the Red Hat 8.0 distribution. This choice would be different for highly secure machines such as firewalls, where OpenBSD would be used in conjunction with GNU/Linux.
The major server functions are delivered by:
The MTA (Mail Transport Agent) is Exim, because it is a fully-fledged product comparable to Sendmail in scope, but easier to maintain. It also understands Sendmail options can therefore be run as a compatible replacement for Sendmail. Postfix would be an acceptable alternative.
The MAA (Mail Access Agent) is Courier-IMAP which was felt to be easier than Cyrus because it has a simpler mailstore. However Cyrus would be a good choice.
PhpGroupWare or the Horde would make very good web based solutions. The new Kroupware has not been evaluated.
Apache is chosen because it is the market leader with a wide range of associated tools and support. Other servers could be used for specific tasks; for instance, Zope (see 11.4.2 below) could be used for content management.
Now that Aswad (see Section 11.4.3) seems to have stopped there is no reference solution. The discussion in Section 11.5 indicates that there is some choice available here.
For large databases which are principally read-only, MySQL; for other kinds of databases PostgreSQL.